Were you aware that the Welsh annals of the kings (of the Britons) which contain all that marvelous stuff about King Arthur also have an accounting of the initial stages of the Dark Ages ~ right there about 538-540 AD too ~ crops failed, it got cold, trees lost their leaves, people starved, the whole land was laid waste.
And that's the good part.
Bet you thought those guys were telling fairy tales.
No, it doesn't. It has to do with denigrating the period in comparison to Classical Rome. The concept you seem to have of "conditions were so primitive outside of Spain that I doubt "Europeans", as a whole, could come to a resolve about anything other than building more dongeons" is simply in error.
The idea of five hard years in the mid-500s determining what the Franks were doing in 730 is silly. A longer "small ice age" in the 16th through 18th centuries didn't stop the Renaissance and Enlightenment, nor did the massive die off of population in the plague years stop late Medieval civilization. In both cases the hardships spurred new social development.